Static light scattering data on extremely dilute solutions (in the range 1 x 10(-5)-9 x 10(-3) g cm(-3) and 15-45 degrees C) of a typical nonionic surfactant (C(12)E(6)) recently reported by us have been analyzed by using various thermodynamic models for micellar growth. It has been shown that the effects of intermicellar interactions can be neglected in such a low concentration range, The observed concentration dependence of light scattering intensity cannot be explained if we do not take into account pronounced change in the thermodynamic stability of micelles at a certain aggregation number q which is relatively close to the aggregation number of the small (globular) micelle (similar or equal to 110) formed at the critical micellar concentration. This suggests that micellar shape changes significantly when globular micelles begin to grow into rodlike micelles. Such early steps of the elongation process has been previously suggested by Forte et al. (J. Phys. Chem, 88, 5713 (1984) and 90, 5746 (1986)) on the basis of magnetic birefringence and viscosity data on concentrated solutions of a cationic surfactant, However, the present study is the first one which analyzes the experimental data quantitatively without any problems concerning treatment of intermicellar interactions.